The present invention relates to improvements in container closure systems which are used for products which require autoclave sterilization processing. In these applications, it is important that the integrity of the sleeve be maintained. It has been found that in conventional systems due to the temperature variations of the process, in some instances thermal creep in the materials during autoclaving, which in prior art closures, caused a loosening effect producing in some instances breach of the seal. Maintaining a tight seal during the autoclaving process is important to maintain the integrity of the product. The present invention provides a closure system characterized by novel features of construction and arrangement ensuring a tight seal during autoclaving processes,
The present invention provides a closure system particularly characterized by features which make it particularly useful in autoclaving processes. To this end, the closure system comprises a sleeve-like insert which may be press fitted on the neck finish of a container having a spiral configuration terminating in a locking portion and a cap having lugs which engage in the slot and lock a liner in place in a sealed condition on the container.